Flanged pipe product



a company of Delaware [54] FLANGED PIPE PRODUCT 5 Claims, 4 DrawingFigs.

[52] U.S.Cl 138/109, 285/410 [51] Int.Cl Fl6ll9/02 C I i United StatesPatent 13,533,449

[72] Inventor Jay S. Gallinger [50] Field oi'Search l 38/109,

Wilmington, Delaware 96; 285/390, 410, 366; 72/124 21 A I. No. 79l,046iZZi Fii e d Jan, 14, 1969 [561 References Cited Continuation-impart ofSer. No. 569,881, UNITED STATES PATENTS g- 1966,119W Patent 3,451,2432,941,823 6/1960 Good 285/410X [45] Patented Oct. 13, 1970 TS [73]Assignee Galaxie Manufacturing Co. FOREIGN PATEN Wi i Delaware 638,0773/l962 Canada 135/109 Primary Examiner- Louis K. Rimrodt Attorney-Cushman, Darby and Cushman ABSTRACT: A flanged pipe includes concentricserrations which are formed on a face of the pipe flange without cuttingany material from the flange. The serrations are formed by a rollingaction which displaces material and which substantially eliminatesresidual tension stresses in the finished product.

Patented Oct. 13,1970 3,533,449

Sheet L of 2 1/ v INVENTOR J2) J5. flay/W58 I ATTORNEY5 Patented Oct.13, 1970 Sheet 3 012 i Z6 X INVENT OR JIQY ,3. any/vase FLANGED PIPEPRODUCT This application is a continuation-in-part of my copendingapplication Ser. No. 569,881, filed Aug. 31. I966 now US. Pat. No. 3,45L243 granted June 24, I969.

BACKGROUND AND BRIEF DESCRIPTION OF INVENTION This invention relates toa novel pipe product having a flange formed integrally with the pipe andhaving serrations formed in a face of the flange. The serrated flange ischaracterized by its properties of being stronger, more resistant tofatigue and corrosion cracking. and more easily manufactured than priorserrated flanges which have been assembled on pipes.

Generally, it is known to form a smooth flange on the end of a pipe sothat the flange is an integral structure with the pipe. A method forforming such a smooth flanged pipe is shown in Lindberg US. Pat. No.1,421,507, and various types of ap paratus have been utilized to producesuch flangesl Also, it is known to cut concentric serrations in separateflange pieces which are assembled as end portions to pipes, such asshown in Albro US. Pat. No. 3,253,449, and such serrated flanges aremanufactured by actually cutting and removing material from the face ofa flange piece. In my copending application, as identified above, I havedescribed methods for simultaneously forming serrations and flanges asintegral structures of pipes. This application is directed to a pipeproduct which can be produced with an integral, lapped flange which issufficiently strong to be serviceable under a wide range of conditionseven though serrations are formed into the flange. Prior to my owninvention, it has been considered a practical impossibility to provide astrong, flanged, integral pipe structure by the known processes ofcutting and removing material from the lapped end of a pipe.

The product of the present invention comprises a pipe having a radiallydisposed flange formed by lapping an end of the pipe. The flange has asubstantially flat face which can be abutted against a similar flangeface of an adjoining pipe (or against a gasket between flanged pipes),and the flat face of the flange includes serrations which are formedinto the face without substantially reducing the thickness of the flangeand without removing any of the material from which the flange isformed. It has been found that the pipe product which results from arolling displacement of material from the surface of a flange results inan improved product in which substantially all residual stresses arecompressive. This product is in complete contrast to pipes havingserrations formed by cutting and removing material inasmuch as a cuttingor machining operation results in a surface having residual tensionstresses. In many chemical services, materials fail from a type offatigue known as stress corrosion cracking which is caused by acorrosive environment as combined with residual tensile stresses in amaterial. Thus, it is desirable and preferred to eliminate residualtension stresses as much as possible, and, in fact, it has been a priorpractice to treat a machined surface to induce compressive stresses soas to extend its fatigue life. Typically,

a machined surface is treated by shot peening to induce such compressivestresses. The present invention eliminates any requirement for costlytreating steps or special assemblies for flanged pipes, and the improvedpipe product of this invention can be easily manufactured as a unitarystructure in accordance with the method described in my copendingapplication.

These and other advantages of this invention will become apparent in themore detailed discussion which follows, and in that discussion referencewill be made to the accompanying drawings which will be brieflydescribed below.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 represents an overall perspectiveview of typical apparatus which may be used to form a flanged pipeproduct of the type contemplated by the present invention;

FIG. 2 illustrates in cross section a portion of a pipe end which isbeing held in a die shell to receive lapping and serrating operations,and an initial step in a typical process as illus- 1 trated;

FIG. 3 illustrates a further step from that shown in FIG. 2, and in thisstep the flange is partially formed to a position which is slightly lessthan its final relationship to the main body ofthe pipe; and

FIG. 4 is a similar view to FIGS. 2 and 3 and illustrates a final stepin a typical process for finishing a flange and for simultaneouslyapplying serrations to a face of the flange tp form the pipe product ofthis invention.

DETAILED DESCRIPTION OF INVENTION Flanges may be formed as integralstructures with end portions of pipes by working and bending an endportion ofa pipe radially outwardly against a die surface until adesired development ofa flange has been attained. This type of flangeformation is considered a lapping operation, and the prese ht inventionis particularly concerned with flanges formed by such a lappingoperation. As already mentioned, the Lindbe r g patent illustratessuitable apparatus for developing a flange at a pipe end. The apparatusillustrated in the Lindberg patent is an example of an early arrangementfor forming pipe flanges, but more recent apparatus places a rollermeans against inner surface of a protruding pipe section for working theprotruding section against a die shell in which the pipe is heiqi. Suchapparatus includes means for pneumatically or hydrauiically positioningthe roller device so that its axis of rotation rnay be changed relativeto the longitudinal axis of the pipe. In this way, a roller means may beinitially placed against the inside surface of a pipe end and rotatedaround the circumference of that surface to work that surface into acondition for shaping. The same roller means is then slowly adjusted inits position relative to the pipe so that the axis of rotation for theroller moves away from the central axis of the pipe, and thus the pipeend is ultimately developed into a flange which extends radiallyoutwardly from the pipe and at approximate right angles to the centrallongitudinal axis of the pipe. Such apparatus is well known in the artfor lapping or flanging pipe ends, but prior methods have requiredadditional apparatus and separate operations to finish formed flanges soas to include concentric serrations in their exposed faces.

In order to illustrate a method for forming the product of thisinvention, FIG. 1 shows typical apparatus which may be used forsimultaneously forming and serrating a flange on a pipe end withoutcutting any material from the flange face. A die shell 10 is designed tocarry a pipe section 12 which is to be formed with a flanged end, andthe pipe section is placed in the die shell so as to leave an endportion 14 protruding therefrom. In the illustration of FIG. 1, the endportion has been worked radially outwardly from the longitudinal axis A-A of the main pipe body so as to develop the illustrated flange on theend of the main pipe body 12. FIG. 1 also shows a roller means 16positioned adjacent to the die shell for a working contact with theprotruding end portion of the pipe. The roller means 16 includes asmooth working portion 18 which contacts the inner surface of the pipeend to develop it into the flange which is shown. Of course, the rollermeans 16 is suitably mounted on apparatus which can be moved toward andaway from the die shell 10, and such conventional apparatus has beenomitted from the drawings for clarity since machines of this type arewell known in the art. The apparatus which carries the roller means 16also includes means for moving the roller means relative to thecircumference of the pipe end, and additionally, control means areincluded for changing the angle C between the central longitudinal axisA-A of the pipe and the axis of rotation 8-8 of the roller means. In atypical apparatus, the roller means is driven about its axis B-B whilebeing orbited around the axis A-A of the pipe so as to contact anddevelop the protruding end portion of the pipe. As the flange isdeveloped, atypical apparatus includes pneumatic means for changing theangle C between the axes A -A and B -B so that the roller means 16causes the pipe end portion to bend outwardly against an outside surfaceof the die shell 10.

FIGS. 2 through 4 illustrate a series of steps in a process forproducing the product of the present invention, and the apparatus usedis similar to that described for FIG. I. At the beginning of the processa pipe 12, or whatever other tubular structure is being worked, isplaced within a bore of the die shell so that an end portion 14 of thepipe protrudes out of the die shell, as illustrated. Then, the apparatuswhich carries the roller means 16 is moved toward the protruding endportion of the pipe to contact the inner surface of the end portion. Theinitial contact between the smooth-surfaced roller 16 and the protrudingend portion of the pipe is shown in FIG. 2, and once the roller means isin position, the apparatus can be operated to orbit the roller about theentire circumference of the pipe end. As the roller means is orbited,the roller rotates on its axis B -B, and the smooth surface 18 of theroller begins to work the material of the protruding pipe portion.

Then the roller means I6 is slowly adjusted, such as by pneumaticcontrol devices, to apply a pressure against the inner surface of thepipe end, and as the axis B -B is changed relative to a longitudinalaxis of the pipe, the end portion is flared radially outwardly to form aflange. FIG. 3 illustrates the partial formation of a flange, asdeveloped from the end portion 14 of the main pipe body. In the FIG. 3position, the v roller means 16 has been adjusted from the initialposition shown in FIG. 2 so as to develop a flange which approaches anapproximate 90 angle relative to the longitudinal axis of the pipe.However, it has been found that the desired serrations for such a flangecan be developed during the flange forming operation if thesmooth-surfaced roller is replaced by a serrated surfaced roller priorto the completion of the flange forming sequence.

FIG. 4 shows that the roller with a smooth surface 18 has been replacedby a roller 20 having equally spaced annular grooves or serrations cutinto its flange contacting surface. When the serrated roller 20 isengaged with the exposed flange surface (which was initially the innersurface of the pipe end 14), there are formed concentric serrations inthe flange face corresponding to the grooves cut into the roller 20.After the roller 20 is engaged against the exposed flange face, it isthen moved further by the above-mentioned pneumatic means to press intothe flange surface and to form the concentric serrations therein. Thisformation of serrations is a result of a rolling displacement ofmaterial into the grooves cut into the roller 20 and away from contactpoints between the roller and the flange surface. This displacement isaccomplished with substantially no reduction in thickness of the flangeand with substantially no residual tension stresses left in the flangeface. In fact, the rolling displacement of material results in residualcompressive stresses which are of less concern to corrosion crackingproblems than are tension stresses. The resulting serrations areconcentric and have flat areas between each groove, as shown in thelower portion of FIG. 4. In a preferred process, it has been found thatthe step of forming concentric serrations in the flange face should becarried out before the flange is fully formed to its final position. Ina typical flange formation, it is desired to produce a flange whichextends radially outwardly from a pipe body at an angle of approximately90 as related to an axis of the pipe body. When such a flange 5 is to beformed, it has been found that the initial steps of the process, whichmay include the use of a smooth-surfaced roller, should be applied untilthe flange is partially formed to a position within the range of 86 to88 as related to the central longitudinal axis of a uniform diameterpipe. When this partially formed flange has been produced, the pipe isremoved from holding dies, and the smooth-surfaced roller is replaced bya serrated surfaced roller 20. Then the pipe is reinserted in theholding dies, or die shell, and final forming and serrating takes placewhile the flange is being developed to its final position ofapproximately 90 as related to the pipe body. FIG. 4 illustrates t efinal position of the serrated rol er for forming such a 90 flange, andalso a specially shaped die shell is illustrated wherein the uprightface portion 24 of the die shell is shaped to receive the back side ofthe formed flange. The usual die shell face is flat as indicated by thedotted lines X -X, but the die shell which is illustrated is built up tosupport the flange during the serrating operation. Also the corner 26 ofthe die is shaped with a radius to accommodate the formed radius on theback side of the flange.

As an example of a product of the present invention, a serrated flangehas been produced which has spaced serrations having flat topped peaksof approximately .020 inches in width and having groove walls betweenthe peaks that are at 45 angles to the flat peaks. Pipe sizes rangingfrom one-half inch to six inches (with outside diameters from .840 to6.625 inches) have been formed with serrated flanges having outsidediameters for the laps ranging from 1% inches to 8% inches. Theserrations formed in the various pipe sizes are of the desiredconfiguration and offer improved characteristics over machinedserrations formed by separate processes. This invention is useful forpipe products made from various metal materials, such as copper,aluminum, brass, carbon steel, Monel, nickel, Inconel and stainlesssteel, and also for nonmetal materials such as thermoplastic materials.

Iclaim:

I. An improved unitary pipe product having a flange formed by lappinganend of a pipe body, with said flange having a substantially flat facewhich can be abutted against a similar flange face of an adjoining pipe,and including serrations formed on the surface of said flat face withouta substantial reduction in thickness of the flange and without removingany of the material from which the flange is formed, thereby providingan improved pipe product having a strong, un-

